ABL1 and myeloid leukemia: A follow-up report using the same p210 BCR-ABL protein (b3a2) in BALB/c BM transduction/transplant studies, compared another p210 BCR-ABL protein (b2a2), resulting from an alternative breakpoint, when driven by a murine stem cell virus (MSCV) U3 promoter found that both gave rise to B ALL without any evidence of myeloid leukemia (49).